| Description |
In recent times, Dirac materials that exhibit gapless excitations near the Fermi level have attracted great interest due to their promising applications in electronics, thermoelectric, superconductors, device applications, and quantum computing. This study is based on a comprehensive investigation of a novel 2D Dirac material black phosphorus/phosphorene and 3D Dirac materials of selected tellurides, tin-Telluride (SnTe), copper telluride (Cu2Te), and zirconium telluride (ZrTe) that encompasses the synthesis methodology, structural characterizations, density functional theory simulations, and their applications. The last few years have witnessed a great shift in research from conventional 2D materials and TMDCs (Transition Metal Dichalcogenides) to new single element 2D materials, known as phosphorene (black phosphorus). Pristine and doped black phosphorus were synthesized by polymorphic phase transformation, which were later used to compare their optical and electronic properties. Frequency dependent dielectric functions of the anisotropic zigzag and armchair edges of phosphorene suggested that incorporation of various metallic and nonmetallic elements in black phosphorus facilitated better tunability of the band gap. Synthesis and development of new Dirac materials by disturbing the SnTe symmetry was accomplished by substitution of a Sn vacancy by P that maintained the intrinsic band inversion at the L point along with reduction of the direct band gap as iv calculated by first principles. Moreover, the modified effective mass, lattice imperfection, and enhanced conductivity as a result of doping resulted in a large memory window ~ 3.1 V for ferro-electric field effect transistors (FeFET) accompanied by a large change in current within a certain potential range. Copper telluride (Cu2Te), a member of the chalcogenide family, has emerged as a state-of-the-art thermoelectric material with low thermal conductivity and high thermoelectric (TE) performance; however, this material exhibits exceptional transport properties only at very high temperatures. We investigated the synergistic effects of Ga doping on the TE performance by first principle calculations along with experimental validations. The enhanced electrical conductivity, thermopower, and moderate thermal conductivities led to the optimized TE performance in 3 atomic % Ga doping (Cu1.97Ga0.03Te), exhibiting a ZT value of 0.46 at 600 K, almost three times that of pristine Cu2Te in this temperature range. |
